The stockpiling of components within the framework of future delivery obligations of control devices once the production has ceased entails financial risk. If not enough components are kept in stock prior to the discontinuation, then a costly post-production development looms, which ultimately must serve the entire variance in the field, however. If too many components are stockpiled, then the stock-keeping will cause expense, and components must also be scrapped once the post-production delivery obligation has expired. The most critical component in the stockpiling is the microcontroller, since it is the most complex, expensive and also the most risky component in a post-production control device development, especially the software. Moreover, for the micro controller, in particular, there still exists no (identical) second source.
One approach for solving this problem is to implement the software modules of the no longer available microcontroller in an FPGA (field-programmable gate array) and to mount it on an MCM (multi chip module) in the otherwise old packaging and mechanisms of the control devices. However, this presupposes that the software of the complete no longer available microcomputer is still in existence. When developing the microcontroller, this software would most likely have to be developed as well and ultimately be available in all supplied variants, development stages and derivations. Furthermore, the FPGA would have to a high number of gates. It must be assumed that a current FPGA is able to represent a one year old microcontroller in the first place.
Another approach is to network the hardware modules of the no longer available microcontroller from identical hardware modules of various available microcontrollers on an MCM, for example, and to mount it in the otherwise old packaging or mechanisms. This is a typical control device measure in the development of new microcontrollers, in which a development board is created from existing modules of microcontroller families of the particular manufacturer. For example, the first evaluation board (EVA) of the Golden Oak consisted of 2 microcontrollers, and the time processing unit (TPU) was used from one of them, and the other modules from the other. The communication of the separate modules must be implemented via the external bus of the microcontroller, which may entail performance losses as a result of the slow external communication. The software within the sense of a universal control device would therefore have to be modified or expanded by at least the external communication of the x microcontrollers.
Another approach suggests a complete replacement of the no longer available control device by a control device of the next control device generation, either with a compatible plug or with a plug adapter. It is assumed here, however, that a customer- or project-specific newer control device of the next control device generation exists. The additional functions produced as a result of the further development, or the additional software would have to be disabled. Moreover, it is assumed that no functional concept breaks or software changes or a functional re-design have taken place, if the outlay in connection with the change is to be restricted to the data application alone. Presumably, a software release would have to be used following the migration between the control device generations.
Given the. many uncertainties, none of the previously known approaches therefore offers a reliable management of the stockpiling problem.